v0.40.8

What's Changed test(consensus): backport TestStateOversizedBlock flake fixes to v0.40.x by @rootulp in #3145 fix(ci): bump Go to 1.26.4 on v0.40.x to fix govulncheck by @rootulp in #3142 fix(types): validate nil SignedHeader in LightClientAttackEvidence (backport #2923 ) by @mergify [bot] in #3220 fix(ci): resolve govulncheck failures on v0.40.x by @rootulp in #3221 chore: drop changelog system on…